Gap Inc. (GPS, news, chart) is seeing three times normal trading volume on increasing action in August and December calls. 10,480 of the August 17.5 calls have traded, compared to open interest of 7,994. Today’s volume includes three large blocks (3,051, 2,25, and 2,121 contracts) of August 17.5s calls trading bidside or for 25 cents a contract. Meanwhile, blocks (2,117, 1,761, and 1,089 contracts) of December 17.5 calls traded askside or for $1.50 a contract.5,052 contracts have traded, compared to open interest of 3,040. Therefore, while the August 17.5s are being sold to open, it seems that the Decembers are being bought and some of today’s volume might be tied to rolling (closing August and opening December) or to calendar spreads. Shares are trading up 43 cents to $16.56. Earnings are due out August 21 and after the August contracts come off the board.